| The recovery technology of the first concentrated waste liquor of ethanol reed pulp cooking waste liquor is studied in this paper,the waste liquor of the other two stages was recovered for cooking stage directly.After testing pollutant standards index,the conclusion are:pH value was 3.77,CODcr was 106.0g/L.solids content was 52.5g/L.The solid content in waste liquor includes lignin,oligosaccharide and little ash;the liquid ingredient was analyzed by gas chromatograph,and the gas chromatograph parameters were:infection temperature was 200?,programme temperature rising was 758 and keep 1min,rising to 180? by a 5 ? increasing per minute,kept 1 min in 180?,detector temperature was 210?,columns was CP WAX 58CB.The conclusion of gas chromatograph analysis is:waste liquor contained lots of ethanol,little furfural,formic acid,micro ingredients and amount of water.The lignin and oligosaccharide in waste liquor was separated and extracted.The separation of lignin consists of two parts:lignin a and lignin b.Some concentrated waste liquor waws attained after cooking,and they were collected in a reagent bottle and put in the refrigerator for 24h,lots of lignin precipitated,separated the lignin precipitation and the supernatant,that was the lignin a.The yield of lignin a was 7.75g/L,the purity was 74.6%by klason lignin testing method,supernatant is called supernatant A.Diluent B was got after adding water in supernatant A,the dilution multiple was 0.6.Put the diluent B in refrigerator for 24h,the lignin would precipitate continuously,and thses were called lignin b.The yield of lignin b was 12.89g/L,the purity was 89.41%.Diluetion B was treated by vacuum distillation and the oligosaccharide solid was attained,the yield was 32.11g/L.The carbohydratethe content was determined by DNS method.The carbohydratethe content was 64.4%by determining xylose content,while the content was 64.9%by determining glucose content.Furfural and ethanol mainly were contained in fraction C of below 78? after analysis by chemical and instruments.Do atmospheric distillation of fraction C,distillate E above 97 ?and fraction F below 97? were attained.The volume ratio of E and F was E/F=1/16,and the main component of E was furfural.Extract the furfural in E,the best extraction condition were:extractant was trioctylamine,the best extraction temperature was 20 ?,and the ratio was 2:1,the extraction rate was 72.36%.The main component of fraction F is ethanol,the ethanol content was 60,which was a high level and could be used at cooking stage.In the liquid which was fraction D attained above 78?,formic acid was mainly component after analysis.Method of producing formic acid by sodium formate was used to extract formic.First change the formic acid of fraction D into sodium formate,separate the sodium foramte,and heat the sodium formate and sulfate together to produce formic acid.The best extraction condition of formic acid was:sulfate concentration 62%,usage was 2.1 times,reation temperature was 50?,and reation time was 45min.The extraction rate was 91.8%.Distillate H is attained after recycle formic acid in fraction D.After gas chromatography,distillate H has low ethanol content,and can be used at pulp washing and other stages.In a cooking waste liquor treatment cycle,ethanol recovery rate is 79.4%,recovery amount of formic acid and furfural was 0.0177mol,0.0457mol per 100g raw material.The letters used in paper can be found in appendix C. |
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