Evaluating and improving environmental performance of HC's recovery system: A case study of distillation unit

Waste solvents/valuable products in the effluent stream are one of the major environmental problems in the chemical industry if not properly controlled. Separation processes are vital for the recovery of waste solvent/valuable product from the effluent stream to reduce the pollution along with improvement in economic performance. Among the various separation processes, distillation is most widely used. A number of environmental indicators, each satisfying researchers own need, and methodologies such as life cycle assessment (LCA), minimum environmental impact assessment (MEIM), waste reduction algorithm (WAR) and environmental fate and risk assessment (EFRAT) are available for evaluation of environmental performance of chemical processes. In this article, a systematic procedure, introducing an environmental performance index (EPI) based on potential environmental impact (computed from waste reduction algorithm (WAR)), energy consumption, resource conservation and fugitive emission, for evaluating environmental performance is presented. Analytical hierarchy process (AHP) is used at two levels for the determination of weighting of individual categories. The procedure is applied for the study of environmental performance of distillation column (steam stripping column) from a real chemical plant for the recovery of acetone and HC's from the off gases of the distillation fraction (DF) plant. Alternatives are compared using environmental performance index and best alternative is selected.     

Nanofiltration of wastewaters from the fish meal industry

The wastewaters generated in the fish meal industry, a water-intensive industry, contain a high organic load comprising a significant amount of proteins. Therefore, they should not be discharged without a suitable treatment in order to prevent negative impacts in the environment, and allow the recovery of high added value products. The effluent generated in a fish meal plant located in Talcahuano, Chile, was characterized, and pre-treated by microfiltration (MF) cartridges in series (80, 20 and 5 μm). A multi-channel ceramic membrane of 1 kDa MWCO, Kerasep NanoN01A, was used in the nanofiltration (NF) experiments. The operating conditions were optimised in total recycling mode, and the subsequent concentration experiment was carried out at 4 bar, 4 m/s, ambient temperature and natural pH. The results from this work clearly show that NF is an efficient and ecologically suited environmental technology for decontamination and recycling of the wastewaters generated during the fish meal production, as it allows both the recycle of water (permeate stream) and proteins (concentrate stream) into the fish meal process, besides environmental pollution abatement. Although the membrane undergoes severe fouling, it can be effectively cleaned through a basic-acid washing cycle.     

Processing ofcrambe abyssinica seed in commercial extraction facilities

Crambe abyssinica seed was processed in four commercial oilseed crushing facilities, two utilizing prepress solvent extraction and two utilizing straight solvent extraction techniques. Mill capacities ranged from several T/day to 200 T/day. Crambe throughput in the larger facilities ranged from 30 to 150 T/day. Seed, press cake, flakes and finished meal samples were collected and analyzed during and following the runs. On-site testing included measurements of moisture, oil, glucosinolate and temperature and estimates of thioglucosidase enzyme activity. Three to 7 T of defatted meal were produced for each of four beef cattle feeding studies, and oil produced was blended into commercial erucic acid production streams. Except for one run, thioglucosidase inactivation had to be completed in the desolventizing/toasting (DT) unit, and the high temperatures required resulted in destruction of glucosinolate and the formation of aglucon product, 1-cyano-2-hydroxy-3-butene, and glucose in the finished meals. Protein solubility and lysine levels decreased with excessive heat. Regression analysis was used to examine some of the data for relationships between temperature, moisture, glucosinolate, nitrogen solubility and aglucon products. The results of these runs further demonstrate the feasibility of processing Crambe in commercial oilseed facilities. Retired.     

Reverse osmosis applied to metal finishing wastewater

The electroplating industry is a great water consumer and, as a consequence, one of the biggest producers of liquid effluent. The metal finishing industry presents one of the most critical industrial waste problems. There is therefore growing interest in developing methods for reclaiming metals from plating waste stream and recovery of water using membrane technology [1,2]. The application of reverse osmosis (RO) to the global effluent from the electroplating industry has been studied in this paper. The results obtained show that there is 75-95% recovery of water and nearly total removal of metals in the permeate.     

Sunflower processing technique

A great deal of interest has recently been shown in sunflower seed as an oilseed erop. The introduction of new Russian seed varieties with higher oil content have helped to stimulate this interest, particularly in the flax and cottonseed growing areas. This paper presents background material pertinent to the subject of sunflower processing. Such things as seed structure, oil and meal quality and certain economic considerations are included. Processing techniques currently used are discussed and comparisons made with the processing of other oilseeds. Brief mention is made of storage and handling of the seeds, meal and oil. Extraction is discussed briefly, but since it is successful only if the seed is properly prepared, seed preparation and handling prior to extraction are stressed. Sunflower seeds are nearly 30% hulls and these hulls are high in crude fiber content. For this reason, dehulling and hull separation practices are important aspects of processing sunflowers. Expeller operating variables are also important where prepressing is part of the process. These processes are stressed. Direct solvent extraction and prepress solvent extraction methods are currently being used successfully. Features of both methods and their applicability are discussed along with seed preparation needed for each method. One of nine papers to be published from the Symposium on Solvent Extraction Techniques for Soybean and Other Seeds, presented at the AOCS Meeting, Minneapolis, October, 1969.     

电泳萃取技术用于萘酚绿B的回收

电泳萃取是一种新型的电泳与萃取技术耦合的分离技术。本文应用这种新型分离技术以正丁醇为萃取剂回收萘酚绿Ｂ, 在自行设计的电泳萃取池内实验研究了电泳萃取过程中的传质动力学过程, 研究了电场强度、溶质浓度等因素对于回收率及传质通量的影响。实验结果表明, 随着电泳萃取时间的增长, 回收率不断增大;电场强度的增大可以有效地提高溶质的回收率, 传质通量也随之增大; 而料液的初始浓度的增大会使传质通量增大,回收率有所下降。由回收率的大小可以看出, 电泳萃取分离技术是一种很好的处理染料废水的方法。     

The technical developments of the oil solvent extraction industry in China

The development of the oil solvent extraction industry in China is described. The first continuous oil solvent extraction plant (modeled on a Rotocel extractor) was built in 1955. Since then, other types of extractors have been installed and processes such as the desolventizing of extracted meal, the evaporation of miscella and the recovery of solvent vapor have been adopted. This essay documents improvements in technology and machinery and discusses future developments in the industry.     

Practical considerations in commercial utilization of oilseeds

In the past 40 years oilseeds have gained a dominant position in the U.S. agriculture. Soybeans have made more rapid progress in the feed and food industries than other oilseeds because of the low cost in their production, easy adaptability to solvent processing, and importance to the feed and food industries. The foreign markets have been a great asset to the soybean industry. However, each of the other oilseeds is finding its special place in the industry through modification of the seed by plant breeding, the development of new techniques in oil mill processing and other technical modifications. Even geographical location of a crop can be a deciding factor in the economics of successful operation. Production and processing of oilseeds in other countries often presents economic and food acceptance problems that are entirely different than those in the U.S. Both the favorable and unfavorable factors involved in production, composition, processing and conversion of the protein concentrates into acceptable foods are discussed. The recent oilseed research and development which holds promise for increasing utilization of oilseed in foods is reviewed. This includes progress in the breeding of high protein soybeans, new centrifugal techniques for reducing the gossypol in cottonseed meal, progress in the development and production of glandless cottonseed, processing new varieties of sunflower seed, the potential for new and improved oil solvents, the advantages of extrusion processing of oilseed meals, and other techniques which might be expected to improve the color, flavor, texture and other properties of oilseed proteins for foods. Presented at the AOCS-AACC Joint Protein Short Course, French Lick, Indiana, July 13–16, 1969.     

Rückgewinnung von Lösungsmitteln aus der Abluft

Recovery of Solvents from the Vent Air The economic, safety and hygienic aspects of the recovery of solvents from the vent air of plants that handle solvents are dealt with. Physical laws that enable the quantitative determination of solvent content of vent air are discussed. In an example, the amount of vent air in a solvent extraction plant and its solvent content have been determined. The physical and technical scopes for the recovery of solvent from vent air are outlined and the various system are compared with special reference to the absorption technique.     

Modeling the solvent extraction of oilseeds

A computer model and an experimental procedure for generating data needed in the model have been developed for the oilseed extraction process. The experiments are relatively simple and are performed with a bench-top extractor. Experimental results and modeling calculations are presented for the extraction of cottonseed using hexane, isopropanol and ethanol. The calculations show that in an alcohol extraction using a chill separation, isopropanol’s greater oil miscibility allows for a lower solvent-to-feed ratio than does ethanol. Using the latter solvent, however, achieves lower residual lipids in the extracted meal because recycled ethanol contains less oil than recycled isopropanol. Presented in part at the AOCS meeting in Honolulu, HI, in 1986.     

Effects of processing on the functional properties of canola/rapeseed protein

Canola rapeseed is a major oilseed in Canada, Europe and Japan. Recently, Generally Recognized As Safe (GRAS) status was granted to low erucic acid rapeseed oil for use in the U.S. market. Commercial oil extraction of the seed results in a meal that contains 44% protein and which has been subjected to considerable heat. The meal is presently utilized as livestock feed supplement. A number of processes for the preparation of protein concentrates and isolates from canola/rapeseeds and meal have been proposed, although none have proven commercially viable. In addition to protein concentration, a successful process must reduce the levels of glucosinolates, phenolics, phytates and fiber. These antinutrients present a barrier to the use of canola/rapeseed protein materials in foods. Processes to produce protein concentrates have included water extraction of undesirable compounds from heat denatured, dehulled seed followed by solvent extraction for oil recovery and the isopropanol washing of dehulled, defatted flours. Isolates have been prepared by traditional alkaline extraction, and by acid or water extractions followed by isoelectric, heat or polyelectrolyte precipitation of the protein. Isolates have been chemically and enzymatically modified to improve fooduse properties. In this paper, the effects of various processing methods on the functional properties of solubility, color and flavor of canola protein products are reviewed. Presented at the 78th American Oil Chemists' Society Annual Meeting, May 17–21, 1987, New Orleans, LA.     

Enzyme-assisted extraction of shea fat: Evidence from light microscopy on the degradative effects of enzyme treatment on cells of shea kernel meal

A light-microscopic study on enzyme-treated sliced shea kernels was done to investigate the principles involved in enzyme-assisted shea fat extraction. The raw, ellipsoidally shaped kernels, measuring 1.3 to 2.0 cm, were crosssectioned into slices of about 2-mm thickness, which were then dissected into four or six pieces. These samples were treated with or without enzymes for predetermined periods, fixed and processed for paraffin sections (5 μm). Sections were stained with periodic acid-Schiff base (PAS) or Coomassie blue (CB) to localize the complex polysaccharides and proteins, respectively. The cells of the enzyme-treated samples showed distinct degradation and a high loss of cellular integrity. PAS reaction and CB staining of these cells confirmed high loss of cellular materials compared to control samples. This was also reflected in the increases of the soluble protein and free sugar contents of the effluent water collected from samples after treatment. The oilseed materials during preextraction. They thus support the principle of using enzyme treatments to improve fat yield in solvent extraction systems, as has been reported by various investigators.     

Miscella refining

Miscella refining can be practiced as a batch process or, preferably, as a continuous process with oil concentrations through the range of 30–70% by wt of oil. Miscella refining is preferably practiced at the oilseed solvent extraction plant for the economic reason of single solvent recovery system. Three immediate benefits are lower refining loss, lighter colored refined oil, and elimination of water washing. Various types of chemical conditioning, mechanical conditioning, and combinations of both are discussed for miscella refining certain oils. Blends of compatible crude oils can be advantageously miscella refined and, if desired, winterized or hydrogenated to produce oils with unique properties.     

Prepress-solvent extraction of crambe: First commercial trial run of new oilseed

Commercial-scale equipment was used to process experimentally 36 tons ofCrambe abyssinica seed grown in the western part of the United States to obtain information on the processing of this new oilseed and to determine characteristics of the oil and meal products. The run was carried out for USDA at the Pacific Vegetable Oil Corporation plant at Sidney, Nebraska, February 1964. Process objectives in the study included dehulling, primary oil removal by expeller prepress, secondary oil removal by solvent extraction and control of thioglucosides to obtain good oil quality. A continuous plant operation yielded crude oils and toasted meal that will be compared with similar products from other commercial oilseed processes. Characteristics of the crude oils that have been determined are composition, refining losses and hydrogenation ability. Organoleptic data on the refined, bleached and deodorized oils have been obtained, as well as compositional data on the desolventized-toasted meals. More than 13 tons of meal and 10 tons of oil were prepared. Presented at the AOCS Meeting, Chicago, October 1964. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, USDA.     

乳状液膜法处理含镍废水的原理与研究现状

液膜分离技术具有高效、快速、选择性强的特点，是溶液回收和废水处理的一种有效手段。介绍了几种含镍废水的处理方法。阐述了乳状液膜法处理含镍废水的原理和工艺流程，探讨了乳状液膜工艺中的表面活性剂、流动载体、内水相与膜溶剂的选择，pH值、乳水比、搅拌速度、温度、操作时间及配位效应的最佳工艺条件的确定。提出了液膜法处理含镍废水的研究方法。     

Composition of residual solvent in oilseed marc extracted with aqueous mixed solvents

The amount and composition of residual solvent adhering to, or absorbed by extracted oilseed meats is important in research on the design and control of mixed solvent extraction processes. A rapid method requiring unsophisticated apparatus and instrumentation usually available in oilseed processing laboratories for analysis of the extracted marc is described. This method consists of azeotropic distillation of the solvent from the marc followed by centrifugation of the double-phase distillate in calibrated oil centrifuge tubes, reading the volumes of the lower layers, and obtaining the water content from this reading, and a graph, previously constructed by applying the method to known mixtures. Total volatile matter is determined by evaporation and oven drying. Equations for calculating other volatile components of the marc are given. Data are shown for the recovery and quantitative determination of water, and equations are given for calculating acetone and hexane contents in cottonseed marc extracted with a mixture of these solvents. Presented at the AOCS Meeting, Minneapolis, October, 1969. So. Market. Nutr. Res. Div., ARS, USDA.     

Oilseed Meal Based Plastics from Plasticized, Hot Pressed Crambe abyssinica and Brassica carinata Residuals

With the increased use of plant oils as sustainable feedstocks, industrial oilseed meal from Crambe abyssinica (crambe) and Brassica carinata (carinata) can become a potential source for oilseed meal based plastics. In this study, crambe and carinata oilseed meal plastics were produced with 10–30 % glycerol and compression molding at 100–180 °C. Size exclusion HPLC was used to relate tensile properties to changes in protein solubility and molecular weight distribution. By combining glycerol and thermal processing, increased flexibility has been observed compared to previous work on unplasticized oilseed meal. Tensile results varied from a brittle crambe based material (10 % glycerol, 130 °C), Young’s modulus 240 MPa, strain at maximum stress of 2 %, to a soft and flexible carinata based material (30 % glycerol, 100 °C), Young’s modulus 6.5 MPa, strain at maximum stress of 13 %. Strength and stiffness development with increasing molding temperature is in agreement with the protein profiles obtained. Thus, the highest mechanical parameters were obtained at the protein solubility minimum at 140 °C. Higher temperatures caused protein degradation, increasing the level of low molecular weight extractable proteins. In carinata based materials the strain at maximum stress decreased as the protein aggregation developed. Results presented indicate that both crambe and carinata oilseed meal based materials can have their properties modulated through thermal treatment and the addition of plasticizers.     

Coupling of nanofiltration with microfiltration and membrane bioreactor for textile effluent reclamation

This work investigates the application of a microfiltration–membrane bioreactor–nanofiltration hybrid process for textile effluent reclamation. The indigo blue dye was efficiently retained by the microfiltration membrane (100%), which allows its recovery from the concentrate stream. The membrane bioreactor resulted in chemical oxygen demand (COD) and ammonia removal of 73% and 100%, respectively. Nanofiltration technology was successfully applied to polish textile effluent. The principal cause of flux decline was determined to be concentration polarization. The nanofiltration permeate meets the quality requirements for all processes within the textile industry, while the nanofiltration concentrate can be used for less demanding purposes.     

Influence of world fat and oil consumption on protein supply

Fat and oil consumption has influenced the world protein supply principally through the production of oilseeds among vegetable oil sources, fish oil among marine oils and butter among animal fats. In total amount, oilseed protein production is comparable to world production of protein in red meat and in milk. All oilseed and fish meal protein byproducts and some milk protein byproducts find their greatest use in animal and poultry products production. Increased demand for the latter products with concurrent demand for feed protein has shifted the relative values of oil and meal. Increasingly, oilseed production, like meat production, is producing oil as a coproduct, if not a byproduct, of protein production. Although food use of oilseed protein concentrates is increasing, both as fortificants of traditional foods and in newly developed meat analogs, this market appears unlikely to increase demand for protein concentrates as much as the world demand for increase in animal and poultry products. One of 11 papers presented in the Symposium “The World Supply of Edible Oils and Proteins,” AOCS Meeting, Atlantic City, October 1971.     

The potential of soapstock-derived film: Cottonseed and safflower

Oilseed soapstock is seldom used today for the recovery of fatty acids, but it is often added to oilseed meal. The energy value of oilseed meal is marginally increased by the addition of soapstock. To find alternative uses for oilseed by-products, cottonseed and safflower soapstock samples from industrial plants were characterized using American Oil Chemists’ Society recommended and modified methods. The characterization included moisture and volatiles, phosphorus and nitrogen, neutral oil, total fatty acid amount and individual fatty acid profile, and total gossypol for cottonseed soapstock samples. The characterization indicated that cottonseed soapstock samples contained a slightly larger amount of neutral oil than safflower. These soapstock samples were frozen to −40°C at 40 mm Hg for more than 8 h, thawed, and the low-boiling compounds were removed by evaporation under reduced pressure. The freeze-dried soapstocks were mechanically pulverized in an inert atmosphere until able to pass through a 50-mesh screen. When these freeze-dried soapstock particles were rehydrated with deionized water, the formation of a gel phase was observed. Casting of this gel phase onto a substrate and subsequent drying without heating resulted in a thin film, a liposomelike material, with a uniform thickness of about 0.01”. The lamination capability of freeze-dried oilseed soapstocks by rehydration may be attributed to the formation of multiple bilayer lamellae by phospholipids from the oilseed soapstock. Due to its biodegradable nature, the use of soapstock-derived film as a composite or by itself as an encapsulating agent is highly attractive. The potential of this liposome-like material as a chemical carrier is discussed.