Thermochemical processing of meat and bone meal: A review

Since the Bovine Spongiform Encephalopathy crisis, meat and bone meal (MBM) have been considered animal wastes. Nowadays, these animal residues are generally burnt in cement kilns and disposed of in landfills. However, several technologies are being developed in order to achieve energy valorisation of MBM by means of combustion, pyrolysis and gasification. These thermal treatments of MBM will reduce the environmental impact of landfill and, at the same time, take advantage of the MBM heating value (13-30 MJ/kg). The main results of research into combustion, pyrolysis and gasification of MBM show that the products could be used as fertilizer (solid product) and as fuel (gas and liquid products). The present work aims at reviewing the most significant studies about energy valorisation of MBM and the potential application of the products obtained in these thermochemical processes.     

Comparative studies on the pyrolysis of cellulose,hemicellulose, and lignin based on combined kinetics

The thermal degradation behavior and pyrolytic mechanism of cellulose, hemicellulose, and lignin are investigated at different heating rates from 10 Kmin^?1 to 100 Kmin^?1 with a step-size of 10 Kmin^?1 using thermogravimetric analysis (TGA) equipment. It is observed that there are one, two, and three stages of pyrolytic reactions takes place in cellulose, hemicellulose, and lignin respectively. Isoconversional method is not suitable to analyse pyrolysis of hemicellulose and lignin as it involves multi-step reactions. The activation energies of the main decomposition stage for cellulose, hemicellulose, and lignin are 199.66, 95.39, and 174.40 kJ mol^?1 respectively. It is deduced that the pyrolysis reaction of cellulose corresponds to random scission mechanism while the pyrolysis reaction of hemicellulose and lignin follows the order based reaction mechanisms.     

Effect of cellulose and lignin content on pyrolysis and combustion characteristics for several types of biomass

Fundamental pyrolysis and combustion behaviors for several types of biomass are tested by a thermo-gravimetric analyzer. The main compositions of cellulose and lignin contents for several types of biomass are analyzed chemically. Based on the main composition results obtained, the experimental results for the actual biomass samples are compared with those for the simulated biomass, which is made of the mixture of the cellulose with lignin chemical. The morphological changes before and after the reactions are also observed by a scanning electron microscope. The main compositions in the biomass consisted of cellulose and lignin. The cellulose content was more than lignin for the biomass samples selected in this study. The reaction for the actual biomass samples proceeded with the two stages. The first and second stage corresponded to devolatilization and char combustion during combustion, respectively. The first stage showed rapid mass decrease caused by cellulose decomposition. At the second stage, lignin decomposed for pyrolysis and its char burned for combustion. For the biomass with higher cellulose content, the pyrolysis rate became faster. While, the biomass with higher lignin content gave slower pyrolysis rate. The cellulose and lignin content in the biomasses was one of the important parameters to evaluate the pyrolysis characteristics. The combustion characteristics for the actual biomass depends on the char morphology produced.     

γ-Valerolactone from pyrolysis of calcium salts of levulinic-formic acid mixtures derived from cellulose

Hydrothermal degradation of cellulose (DP ∼ 450) in 0.02–0.20 mol dm⁻³ aq. hydrochloric acid at 160 °C, for 2–8 h and neutralization of the filtrate with calcium hydroxide can be used to prepare a mixture of carboxylic acid calcium salts. The mixture consists of calcium levulinate and calcium formate in approximately 1:0.65 mol ratio, together with CaCl₂. Pyrolysis of this crude mixture at 350 °C for 3.0 min produces pyrolyzate oil yield of 140–210 g kg⁻¹ of dry salt mixture. The pyrolyzate was identified as ∼97% γ-valerolactone, with the minor products; levulinic acid, 3-methyl-2-cyclopentenone, and 2,3-dimethyl-2-cyclopentenone by using a combination of GC–MS and NMR spectroscopy.     

Prospective life cycle carbon abatement for pyrolysis biochar systems in the UK

Life cycle assessment (LCA) of slow pyrolysis biochar systems (PBS) in the UK for small, medium and large scale process chains and ten feedstocks was performed, assessing carbon abatement and electricity production. Pyrolysis biochar systems appear to offer greater carbon abatement than other bioenergy systems. Carbon abatement of 0.7–1.3 t CO₂ equivalent per oven dry tonne of feedstock processed was found. In terms of delivered energy, medium to large scale PBS abates 1.4–1.9 t CO₂e/MWh, which compares to average carbon emissions of 0.05–0.30 t CO₂e/MWh for other bioenergy systems. The largest contribution to PBS carbon abatement is from the feedstock carbon stabilised in biochar (40–50%), followed by the less certain indirect effects of biochar in the soil (25–40%)—mainly due to increase in soil organic carbon levels. Change in soil organic carbon levels was found to be a key sensitivity. Electricity production off-setting emissions from fossil fuels accounted for 10–25% of carbon abatement. The LCA suggests that provided 43% of the carbon in the biochar remains stable, PBS will out-perform direct combustion of biomass at 33% efficiency in terms of carbon abatement, even if there is no beneficial effect upon soil organic carbon levels from biochar application.     

Integration between art and science in architectural design

The paper deals with a problem that has been crucial in teaching and practising architectural design since the XVIII century, when the separation between the Academies and the Polytechnics denied the integration between art and science in architectural design. The question becomes more crucial today with the demands arising from the energy saving, environmental awareness and sustainability achievements. An analysis is proposed for focusing the reasons of such a separation and some interventions are suggested in order to improve the efficiency of a design process that composes architectures by means of architectures.     

Hydrogen storage on pyrolyzed chicken feather fibers

Pyrolyzed chicken feather fibers (PCFF) that were prepared by two-step process (215 °C/15 h + 400-450 °C/1 h) demonstrated a significant H₂ adsorption uptake due to their microporous nature. Considering their large availability, cost and H₂ storage capability, PCFF can be a significant, environmentally friendly and bio-renewable candidate to address the H₂ storage problem. A wide range of microporosities was obtained when the second step pyrolysis temperature was maintained between 400 and 450 °C for 0.5-2 h. The optimal H₂ storage was obtained using 1 h pyrolysis in this temperature range. The maximum excess H₂ storage capacity was 1.5 wt% at 77 K and at pressures below 2 MPa. The notable H₂ adsorption of PCFF below 1 MPa can be justified by the abundance of microporosity, and the nanopores available for H₂ penetration. The estimated adsorption energy for PCFFs, 5-6 kJ/mol was in the range of typical physisorption materials indicating the easy recovery of H₂.     

Current status and future prospects for the PVMaT project

The goals of the Photovoltaic Manufacturing Technology project (PVMaT) are to help the US PV industry improve photovoltaic manufacturing processes and accelerate cost reductions for PV components and systems. PVMaT is in its ninth year of implementation, and subcontracts with industry have been completed from four solicitations for R&D on manufacturing process problems. We are in the second year of subcontracts for a fifth PVMaT solicitation.Based on the latest (1998) data from ten PVMaT industrial participants, the average direct manufacturing cost for these producers has been reduced by 29% – from $4.08 to $2.91 per peak watt since 1992 – and there has also been a more than five-fold increase in manufacturing capacity – from 13.1 to 73.3 MW. We believe R&D on manufacturing processes contributes significantly to expeditious reductions in PV manufacturing costs, and we identify areas for future R&D.     

Au/Poly(3-methylthiophene)/10-(p-nitrobenzyl)-2(10H)-phenazinone/Al organic hetero-junction photovoltaic device

We proposed a novel concept of organic two-layer photovoltaic devices with D–σ–A molecule (Donor subunit–σ bond–Acceptor subunit)/conducting polymer heterojunction. Au/PMeT (poly(3-methylthiophene))/NBPN (10-(p-nitrobenzyl)-2(10H)-phenazinone)/Al was fabricated as a prototype of D–σ–A/polymer photovoltaic device. The power conversion efficiency of this photodiode was 5.1 × 10 ⁻²% under white illumination (8.46 mW/cm²). This value was larger than that of PMeT Schottky photodiode. This fact suggests that the concept of D–σ–A/polymer photovoltaic device is effective.     

Thermal – Catalytic cracking of real MSW into Bio-Crude Oil

The thermal decomposition method has been able to convert of real municipal solid waste (MSW) into Bio-Crude Oil (BCO) which is mainly contained hydrocarbon fuel such as light oil (gasoline) and heavy oil (diesel). By this method, sustainable MSW management and energy problem can be considered. Hence, this research was conducted the pyrolysis experimental to BCO production from the real MSW under thermal and catalytic pyrolysis at 400 °C and 60 min for time reaction. To increase the BCO yield in this study, the natural activated zeolite as a catalyst was employed. BCO was analyzed by Gas chromatography–mass spectrometry (GC–MS) which it can be used to identify carbon number range by percentage of peak areas. It was found that the catalytic pyrolysis has performances better than the thermal pyrolysis. Both of thermal and catalytic pyrolysis were the produce of BCO around 15.2 wt% and 21.4 wt% respectively with the main organic components are gasoline and diesel. Furthermore, paraffin and olefin fraction are major species in the gasoline and diesel. It can be concluded that the content of MSW and their processes has an impact on the fuel produced. In the thermal cracking produce BCO with higher content in the gasoline range. More plastic in MSW is also produce more gasoline while more biomass produces more in diesel range.     

International energy R&D spillovers and the economics of greenhouse gas atmospheric stabilization

It is now widely recognized that technological change will play a substantial role in reducing GHG emissions without compromising economic growth; hence, any better understanding of the process of technological innovation is likely to increase our knowledge of mitigation possibilities and costs. This paper explores how international knowledge flows affect the dynamics of the domestic R&D sector and the main economic and environmental variables. The analysis is performed using WITCH, a dynamic regional model of the world economy, in which energy-related technological change is endogenous. The focus is on disembodied energy R&D international spillovers. The knowledge pool from which regions draw foreign ideas differs between High Income and Low Income countries. Absorption capacity is also endogenous in the model. The basic questions are as follows. Do knowledge spillovers enhance energy-related technological innovation in different regions of the world? Does the speed of innovation increase? Or do free-riding incentives prevail and international spillovers crowd out domestic R&D efforts? What is the role of domestic absorption capacity and of policies designed to enhance it? Do greenhouse gas stabilization costs drop in the presence of international technological spillovers? The new specification of the WITCH model presented in this paper enables us to answer these questions. Our analysis shows that international knowledge spillovers tend to increase free-riding incentives and decrease the investments in energy R&D. The strongest cuts in energy R&D investments are recorded among High Income countries, where international knowledge flows crowd out domestic R&D efforts. The overall domestic pool of knowledge, and thus total net GHG stabilization costs, remain largely unaffected. International spillovers, however, are also an important policy channel. We therefore analyze the implication of a policy-mix in which climate policy is combined with a technology policy designed to enhance absorption capacity in Low Income countries. Significant positive impacts on the costs of stabilizing GHG concentrations are singled out. Finally, a sensitivity analysis shows that High Income countries are more responsive than Low Income countries to changes in the parameters. Additional empirical research efforts should thus be focused on the former.     

Hydrogen production from biomass coupled with carbon dioxide capture: The implications of thermodynamic equilibrium

In this work we report on the consequences of thermodynamic equilibrium for hydrogen (_H2)$({\mathrm{H}}_2)$ generation via steam gasification of biomass, coupled with in situ carbon dioxide (_CO2)$({\mathrm{CO}}_2)$ capture. Calcium oxide (CaO) is identified as a suitable sorbent for CO₂ capture, capable of absorbing CO₂ to very low concentrations, at temperatures and pressures conducive to the gasification of biomass. The proposed process exploits the reversible nature of the CO₂ capture reaction and leads to the production of a concentrated stream of CO₂, upon regeneration of the sorbent. We develop a thermodynamic equilibrium model to investigate fundamental reaction parameters influencing the output of H₂-rich gas. These are: (i) reaction temperature, (ii) reaction pressure, (iii) steam-to-biomass ratio, and (iv) sorbent-to-biomass ratio. Based on the model, we predict a maximum H₂ concentration of 83%-mol, with a steam-to-biomass ratio of 1.5 and a Ca-to-C ratio of 0.9. Contrary to previous experimental studies, this maximum H₂ output is reported at atmospheric pressure. Model predictions are compared with an experimental investigation of the pyrolysis of pure cellulose and the reactivity of CaO through multiple CO₂ capture and release cycles using a thermogravimetric analyser, coupled with a mass spectrometer (TGA–MS). On this basis, we demonstrate the applicability of thermodynamic equilibrium theory for the identification of optimal operating conditions for maximising H₂ output and CO₂ capture.     

Status and prospects of photovoltaics in Korea

The Korean National Photovoltaic (PV) Project was initiated in October 1989 to develop technologies for the generation of economically competitive electric power by PV systems. It consists of three stages which will continue until the year 2001. The technical goals and costs targets are directed at solar cell, balance of systems and system application. The objectives are: the development of PV technology through research activities, transfer of developed technology to the industries and diffusion of PV through demonstration projects to the end users. This paper reviews the long-term plan and recent trends in the R&D technology, and shows examples of PV diffusion, demonstration projects and market outlook in Korea. Some activities designed to promote collaboration with foreign countries are also discussed.     

Photovoltaics in buildings: A case study for rural England and Malaysia

This paper presents results obtained from a practical study of photovoltaics in buildings, in rural England and a computer model simulation study in Malaysia. It is a particular application of Building integrated PhotoVoltaics (BiPV) where the PV modules are fitted as partial roofing material. Data from a monitored BiPV-UK installation were analysed and compared with PVSYST 2.0 predictions. This computer model was then used to simulate BiPV applications for the standard school building in Malaysia, enhanced with a thermal computer model SUNREL 1.0β. Whilst cost-effectiveness has been a major issue in its proliferated use, the technology has been without doubt established. Based on the simulated system performances, it can be seen that the application of BiPV technology in Malaysia seems to offer a much better potential as has been expected.     

Synthesis and characterization of potassium iodo hydride

A novel inorganic hydride compound KHI which comprises a high binding energy hydride ion was synthesized by reaction of atomic hydrogen with potassium metal and potassium iodide. Potassium iodo hydride was identified by time-of-flight secondary ion mass spectroscopy, X-ray photoelectron spectroscopy, ¹H and ³⁹K nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, electrospray ionization time-of-flight mass spectroscopy, liquid chromatography/mass spectroscopy, thermal decomposition with analysis by gas chromatography, and mass spectroscopy, and elemental analysis. Hydride ions with increased binding energies may form many novel compounds with broad applications.