我国城市生活垃圾厌氧消化处理的探讨

分析了我国城市生活垃圾处理现状及存在问题，探讨了以厌氧消化技术为主的城市生活垃圾处理方式，为解决我国的城市生活垃圾问题提供参考。     

城市有机生活垃圾高温厌氧转化生物质能研究

在国内外已有的研究基础上,对城市有机生活垃圾的高温厌氧（批量）消化工艺实验进行了初步探索,研究了在55℃的高温条件下累积产气量与消化时间的关系,C／N比与产气量的关系,消化过程中pH值变化,并研究了垃圾高温发酵实验过程中沼气中的CH4和CO2的含量变化,其中甲烷含量最高可达75．3％。实验结果表明,城市生活垃圾高温消化的降解效果较好,产气量较高,启动时间短。     

有机垃圾高温厌氧消化中试验研究

采用高温厌氧消化处理方法对城市生活有机垃圾进行了中试试验研究.其有机垃圾产气量73.4m3/t,产气速率0.52m3/m3.d,COD去除率48.8%.结果表明,高温厌氧消化处理是城市生活有机垃圾较好的处理方式之一.有机垃圾不仅可以得到处理,最大限度地减少其污染环境;同时,还可以产生一定的经济效益和巨大的环境效益.这种垃圾处理方式值得应用和推广.     

剩余污泥与生活有机垃圾联合厌氧消化产沼气研究

以污水处理厂剩余污泥和生活垃圾为发酵原料,研究了不同原料配比对厌氧消化过程及消化效率的影响。结果表明,剩余污泥和生活垃圾联合厌氧发酵可以提高垃圾的消化效率,当剩余污泥和生活垃圾TS比为1∶4时厌氧消化效果最好,经过66 d消化后,COD去除率为59.79%,TS去除率为56.92%,VS去除率为66.87%。     

可生物降解城市生活垃圾厌氧消化基础及工艺研究进展

从动力学和微生物学等基础研究着手、对不同的可生物降解城市生活垃圾的甲烷产率及其影响因素进行详细分析,并比较了目前采用消化工艺,最后通过分析总结指出目前该技术存在的问题以及今后需要攻破的研究难点.     

城市生活垃圾和污水厂剩余污泥联合厌氧消化产气性能研究

以城市生活垃圾和污水厂剩余污泥为消化原料,在中温(35℃)条件下,采用序批式厌氧消化方式,研究了生活垃圾和剩余污泥不同混合比例下的厌氧消化产气性能,以及不同原料配比对厌氧消化过程及消化效率的影响。按照生活垃圾和剩余污泥VS比分别为1∶0(R1),2∶1(R2),1∶1(R3),1∶2(R4)和0∶1(R5),试验设置了5个试验组。研究结果表明:两种物料混合后有助于提高消化效果和产气性能,其中,当城市生活垃圾和剩余污泥VS比为2∶1时,系统厌氧消化效果最好,VS去除率为35.98%,单位VS产气量为348.84 m L/g,产气中甲烷含量为53.8%,消化时间较单纯生活垃圾厌氧消化缩短了9 d。说明一定比例的生活垃圾和剩余污泥联合厌氧消化是提高厌氧消化效率的有效途径。     

水分选有机垃圾三种总固体厌氧消化产甲烷

以水分选城市生活有机垃圾(WS-OFMSW)为原料,采用35L厌氧反应器进行中温(30±2℃)批式厌氧消化,研究3种TSr分别为16.0%、13.5%和11.0%的样品对厌氧消化稳定性及性能的影响。结果表明,3种TSr均能实现稳定的产甲烷过程,pH自我恢复调节能力较强,在整个过程中没有产生挥发性脂肪酸抑制。较低的TSr有助于快速启动并缩短发酵周期,3种TSr厌氧消化分别于32、25和12d达到产气高峰。累积产甲烷量分别为273.1、283.0和313.7L·kgVS~(-1),平均甲烷浓度为64.6%、66.3%和65.7%。3种TSr厌氧消化的VS去除率分别为26.08%、35.76%和41.78%。通过该实验,获得相关的WS-OFMSW厌氧消化原始数据,为城市生活垃圾水分选技术的完善以及有机垃圾厌氧消化性能的提高指出了参考方向。     

TS对城市有机垃圾和剩余污泥联合厌氧消化的影响

在中温(35℃)条件下,以城市有机垃圾和污水处理厂剩余污泥为发酵原料,其中生活垃圾∶污泥=4∶1(w/w,干重),研究了固形物含量分别为3%,4%,6%,8%,10%对厌氧发酵过程及发酵效率的影响。结果表明:当发酵液TS为4%时厌氧发酵效率最高,发酵过程中pH适宜产甲烷菌生长,产气时间长,累积产气量最大,为11 967 mL,且甲烷含量较高;同时发酵过程中氨氮浓度升高缓慢,不会对甲烷菌造成氨抑制,对原料中有机质的降解效果明显,COD去除率为61.7%,TS去除率为47.19%,VS去除率为55.93%。     

基于低温气化和高温熔融焚烧方法处理城市生活垃圾

介绍了一种新的城市生活垃圾焚烧处理方式－气化熔融炉的工艺过程,国外发展现状和研究进展。     

城市有机垃圾车库式干发酵技术

城市有机垃圾处理和资源再生利用已成为我国建设资源节约型和环境友好型社会中迫切需要解决的问题。欧洲国家中以德国为代表的车库式干发酵技术(Garage-type dry anaerobic digestion)已经成熟,可进行规模化的沼气生产。文章着重介绍了车库式干发酵沼气工程的技术要点,并以德国Loock TNS工艺和黑龙江宾县车库式干发酵项目为例,介绍了有机垃圾车库式干发酵喷淋回流、系统密封等关键技术,以期为我国车库式干发酵工程的工艺设计提供参考。     

Gasification of municipal solid wastes: a review on the tar yields

Currently, due to its tremendous availability, the use of municipal solid waste (MSW) as an energy source has received significant attention in China. Moreover, when compared to coal and oil, MSW produces negligible NO_x emissions in the atmosphere and generates less ash. Gasification is a promising technology for converting MSW and other low-value feedstocks into fuel gases and chemicals. In this review article, production of synthesis gas (also known as syngas) from MSW gasification is reviewed, and demonstrated to be a clean and attractive option. First, a short review of MSW treatment techniques and their advantages and limitations is presented, and then, the energy potential of MSW for gasification purposes is evaluated. Second, influencing process factors such as temperature, gasifying agents, gasifier type, particle size, and operating pressure are studied in terms of their impact on the resulting gas quality and quantity. Finally, the potential of key commercial catalysts (Ni-based catalysts, natural catalysts (dolomite), and blast furnace (BF)) in tar elimination is evaluated.     

Air-steam gasification of municipal solid wastes (MSWs) for hydrogen production

Gasification process can be considered as a partial thermal oxidation, which results in the production of a mixture of useful gases (CO, H₂, CH₄, and other gaseous hydrocarbons), little quantities of carbon black (char), ash, and several organic impurities (tar). In this study, we introduced an artificial neural network (ANN) model to simulate the influence of operating conditions on the concentration of products during the gasification process of municipal solid wastes (MSW). Results showed when increasing the residence time, more char is gasified, leading to an increase in the greenhouse gas emissions. It is also found that a further increase in the residence time results in a constant rate of products due to the heat and mass transfer limitations.     

城市生活垃圾典型组分干燥特性实验研究

通过对典型高含水率城市生活垃圾组分（瓜果皮、竹木、纺织物、废纸板）进行低温干燥实验,研究了四种组分在不同温度、通风量及粒径条件下的干燥特性。结果表明瓜果皮、竹木、纺织物及废纸板的临界点结合水含量分别为1．002、0．805、0．398和0．547g／g—DS;干燥温度、通风量、粒径均会对垃圾组分的干燥过程产生影响,且温度对干燥速率的影响比其他两个因素更显著。因此,适当提高温度,同时加大通风量可有效增强干燥效果。     

昆明市春季生活垃圾分析及处理

对昆明市不同生活水平地区的5个垃圾中转站进行抽样分析,将样分带回实验室进行多种实验.分析结果表明,昆明市春季生活垃圾易腐成分含量及其含水率均为最高,分别为60.59%和78.49%;计算了垃圾焚烧的年发电量为4.80x108 kWh,可燃物比率为22.59%,并与秋季数据进行了比较;根据对测定数据的分析并计算各种垃圾焚烧所发的电量,可知昆明市春季生活垃圾的最优处理方法为焚烧发电.     

Optimization of hydrogen production from organic fraction of municipal solid waste (OFMSW) dry anaerobic digestion with analysis of microbial community

Effect of mixed culture bacteria (MCB) addition, initial substrate concentration to inoculum (S_o/X_o), carbon to nitrogen (C/N) ratio on the hydrogen production (HP) from organic fraction of municipal solid waste (OFMSW) via dry anaerobic digestion was investigated. The results showed that supplementation of OFMSW with MCB substantially improved hydrogen yield (HY) and HP. HYs were 306.2 ± 33.0, 149.8 ± 16.6, and 155.3 ± 22.9 ml_H2/gCOD_removed for OFMSW supplemented with MCB, OFMSW, and MCB, respectively. HP at S_o/X_o ratio of 9.2 g_COD/g_VSS was 3.1 times higher than those obtained at S_o/X_o ratio of 1.7 g_COD/g_VSS. The maximum HY of 338.4 ± 18.9 ml_H2/gCOD_removed was achieved at S_o/X_o ratio of 9.2 g_COD/g_VSS. The HP and HY were substantially increased from 169.7 ± 17.1 to 524.2 ± 34.4 ml and from 163.1 ± 23.6 to 338.4 ± 18.9 ml_H2/gCOD_removed with increasing the C/N from 16 to 25, respectively. However, HP and HY decreased at C/N ratio exceeding 26.6. The modified Gompertz equation model was highly fitted to the experimental data with correlation coefficient (R² > 0.984). The 16S rRNA sequences showed the dominance of Pseudomonas fulva with similarity of 99%. Copyright © 2015 John Wiley & Sons, Ltd.     

Pilot-scale high solids thermophilic anaerobic digestion of municipal solid waste with an emphasis on nutrient requirements

A pilot study was conducted to assess the biodegradable organic fraction of municipal solid waste (BOF/MSW) as a substrate in a high-solids anaerobic digestion process. Results obtained indicate that a typical BOF/MSW in the United States is deficient in most macro and micro-nutrients required for robust and stable digestion. The BOF/MSW was supplemented with nutrient-rich organic wastes such as wastewater treatment plant sludges, dairy manure, and synthetic chemical solutions to correct nutritional deficiencies. The combined addition of wastewater treatment plant sludge and dairy manure to a typical BOF/MSW significantly elevated the gas production rate and enhanced the process stability. Microbial nutrient requirements are identified and nutrient concentrations for stable operation are quantified.     

生活垃圾厌氧发酵条件的正交实验

在适当pH值和搅拌条件下，运用四因素三水平L9(3^4)正交实验设计的方法，研究了反应温度、总固体含量、碳氮比、接种物量对于生活垃圾厌氧发酵产沼气的影响。通过对正交实验结果进行分析，得出生活垃圾厌氧发酵产沼气的最佳工艺条件：反应温度54℃，总固体含量25％，C／N比值20，接种物量30％。     

Effect of lime loading on the performance of simultaneous lime treatment and dry anaerobic digestion of smooth cordgrass

The effects of lime loading on simultaneous lime treatment and dry digestion (SLTDD) of smooth cordgrass (SC) were evaluated at 35°C by batch reactors and leaching bed reactors (LBRs). Biogas yields of 1.5%, 3%, and 5% (w/w) lime loadings decreased by 7.1%, 20%, and 75.7%, respectively, compared with no-lime treatment with 198.0 mL/g total solids (TS) by batch reactors. The LBRs with liquid recycling and pH adjustment enhanced biogas production with 148.1–236.1 mL/g TS. The inhibition occurred SLTDD may be ascribed to be high pH and temperature from lime hydration at the initial stage. The activity for methanogenic bacteria was more inhibited than other anaerobic bacteria.     

Low‐temperature pyrolysis of municipal solid waste: influence of pyrolysis temperature on the characteristics of solid fuel

This paper presents the results of pyrolysis experiments of the mixtures of nine different combustibles municipal solid wastes (MSW's main composition: rice 24.33% and fruits 14.60%). The experiments were carried out in a laboratory‐scale reactor under nitrogen atmosphere at temperature of 300–700°C. The study concentrates on low‐temperature pyrolysis of MSWs and the effect of the pyrolysis temperature on the characteristics of the products (solid fuels) including proximate analysis, volatile content, heating value, ignition temperature and density of the solid fuel. The results indicate that the pyrolysis temperature plays an important role on the characteristics of the solid fuels. The volatile content of the solid fuels decreases with the pyrolysis temperature so that the low‐pyrolysis MSW treating process has advantage for higher heating value of the solid fuel for energy recovery purpose. The heating value is in the range of 23–27 MJ kg^?1, equivalent to the heating value of low‐rank coals. Copyright © 2005 John Wiley & Sons, Ltd.