Coastal environment: EC‐cost 48 bioconversion projects and economic aspects

Seaweed has proved to be both a potential resource and a problem for coastal areas. In the framework of the European Communities, a scientific commission was created some 8 years ago, in order to address the matter of seaweed bioconversion in Europe. A book, recently published, represents a fair review and survey of seaweed as a resource in Europe. The matter of seaweed problems and expanded use is now under study in a new programme.

This paper traces back the development and growth of this inter‐European effort and also provides an overview of achievements.     

二氧化碳甲烷化催化剂的研制

本文从化学热力学、催化等几个方面论述了二氧化碳甲烷化催化剂的研制概况．     

Effect of prehydrolysis of milk fat on its conversion to biogas

Milk fat is considered to be the main limiting component of the kinetics of dairy wastewater anaerobic digestion. The objective of this work was to give a better understanding of the nonelucidated anaerobic degradation steps of milk fat. For that purpose, the kinetics of fat degradation was quantified in comparison with other milk components (lactose, proteins), regarding the milk fat polluting load and structure [globular (native state), triglycerides]. This work confirms that milk fat is degraded after a lag phase of several days, with a maximal degradation rate 2 to 5 times less than the degradation rate of the other milk components. It was shown that (1) the structure of the fat does not influence the limits of its anaerobic degradation; (2) the lag phase before biogas production is mainly due to unsaturated free fatty acids (FFA); and (3) conversion to biogas occurs at a lower rate for saturated than for unsaturated FFA. Therefore, the prehydrolysis of fat, which increases the instantaneous concentration of unsaturated FFA, sharply increases the length of the lag phase with no significant change in the maximal biogas production rate. To reduce the delay imposed in the biogas production, it is necessary to reduce the concentration of unsaturated FFA.     

探讨人工燃气中CO含量达标的方法

由于原设计和技术方案等的限制，上海大部分人工燃气中CO含量较高，达不到国标要求。必须寻找一种经济、可靠的方法来降低出厂燃气中CO含量，使之降到10％以下，保证用户能真正用到合格气。     

白豹油田油井化学防蜡效果评价

进行了合成气完全甲烷化催化剂放大制备研究,对放大的催化剂进行了长周期的活性稳定性评价,并对催化剂的失活机理进行了探索性研究。研究结果表明,放大的催化剂经过1 000h的连续运行,CO平均转化率为99.9%,H2平均转化率为99.80%,CH4平均选择性为98.5%,放大的催化剂的反应性能基本达到小试催化剂的性能。对甲烷化催化剂失活的机理进行的研究发现,引起甲烷化催化剂长周期运行失活的原因主要是积炭和烧结,其中烧结是影响催化剂活性下降的主要因素。     

合成气完全甲烷化催化剂的放大制备及失活机理研究

通用电气（GE）和俄罗斯签署了一项战略合作协议,目的是发展俄罗斯的石油和天然气。该合作协议在圣彼得堡的国际经济论坛签署,协议定义了GE和俄罗斯在石油、天然气及其他能源项目合作的关键领域,包括天然气网络的发展、发电设施的发展,液化技术项目的实施、LNG的使用和运输。     

传统合成氨工艺中甲烷化催化剂的失活和预防

文中分析了Kellogg传统型合成氨工艺的特点,阐述了该合成氨工艺中甲烷化炉催化剂的失活和预防措施。对甲烷化催化剂的高温失活、中毒失活、生成羰基镍失活提出了相应的解决办法。     

Thermal,chemical and thermo‐chemical pre‐treatment of waste activated sludge for anaerobic digestion

The influence of different pre‐treatments was studied in order to observe the effects of temperature, pH and treatment time on Waste Activated Sludge (WAS) solubilization, and anaerobic digestion of pre‐treated sludge. Results showed that thermo‐chemical pre‐treatments were the most efficient on Chemical Oxygen Demand (COD) solubilization, which could reach 83% at 170 °C with pH = 12. Yet, increase in COD solubilization in thermo‐chemical pre‐treatment was not linked to an increase in soluble Volatile Solids (VS) as optimal conditions were 170 °C, and 130 °C with pH = 10, for this criterion. So, temperature was found to be the most influential parameter on COD and VS solubilization. Biodegradability batch anaerobic tests confirmed results obtained on WAS solubilization, that is to say that 170 °C and 130 °C with pH = 10 were optimal conditions, with respectively 45% and 21% of anaerobic digestion enhancement. Thus these two conditions were chosen for sludge treatment before continuous anaerobic digestion. Results, after stabilization have shown a better efficiency of 170 °C compared with 130 °C with pH = 10 pre‐treatment, since after anaerobic digestion it led to 71% of COD degradation and 59% of Total Solids (TS) degradation, with an improvement of 54% in biogas production. The main differences between those two pre‐treatments could be due to the pre‐treatments themselves more than to an effect on anaerobic digestion, because the first one led to a partial loss of WAS COD (near 17% of initial COD) and the second one to an increase in TS due to addition of base. Copyright © 2004 Society of Chemical Industry