Research on Intelligentialized Biomass Curing Technology
Shubin Lan ¹, Yang Cao^2,3,a, Zhenhu Pan ¹, Sen Liu¹, Bing Zhou¹, Jianhua Deng¹, Xianhong Zhao¹, Huifen Zhu^1
1Guizhou Provincial Tobacco Company Qianxinan Branch，Xingyi , 562400 , P. R. China
 ²College of Mechanical Engineering，Guizhou University，Guiyang Guizhou ,550025 , P. R. China
³ Guizhou Mechanical and Electrical Equipment Engineering Technology Research Center Co. Ltd., Guiyang, Guizhou ,550025 , P. R. China

First Author: Lan Shubin,  Agronomist, mainly engaged in flue-cured tobacco production technology and technology management research.
Corresponding author: CaoYang, College of Mechanical Engineering，Guizhou University，Guiyang Guizhou , Email: yangc377@163
 
 
Abstract: This thesis focuses on the study of intelligentialized biomass curing house. In order to evaluate this technology and its economic benefit, we have done experiments in an long county of Guizhou province which is a flue-cured tobacco production base. The results show that curing time is a little longer using intelligentialized method. There are no obvious differences in the tobacco-curing process in aspects such as the regularly-set temperature, real temperature and changes of tobacco leaves by either the intellegentialized way or the traditional one. But it takes 1.8 hours longer in each brick bed for the intelligentialized curing house than for the coal-burning curing house. Compared with the traditional curing approach, the intelligentialized biomass curing barn is more energy-saving, less labor-consuming, and has bigger capacity of making quality tobacco so as to improve the benefits of tobacco economy. Therefore， biomass curing barn can be a good substitute for coal-burning curing barn.
Key Words: Intelligentialize curing barn; Biomass; Technology and craft; Benefits of tobacco curing
 
 
 
1 Introduction
The environment problem caused by coal-burning curingis an important issue to be solved. As a renewable energy that is can be transported and stored, biomass is a reliable substitute for coal. Biomass briquette refers to the briquette technology with condensed biomass. In another word, it’s the technology of mechanical loading to process the dispersive, formless, low-density biomass into solid briquettes of high density. The use of biomass in tobacco-curingis supposed to be an efficient way to solve the environment pollution caused by coal burning. Therefore it is in line with the requirement of sustainable development.
2 Materials and Methods
2.1  Experiment Materials
The curing barns in experiment are those in An Long county, Xing Yi county and Xing Ren county respectively. With both a coal-burning barn and a biomass barn in each area. The biomass is made of saw dust, corn through thermo-forming mould technology. The tobacco we chose was the Yun Yan 87 while growing seedlings, field tending, picking technology are in accordance with the regular technology in local farming.
2.2  Experiment Design
The experiment was conducted during 2015-2016. The curing technology and how dry ball’s temperature and wet balls’ temperature are control is seen in the following table.
Table 1 Dry Balls and Wet Balls’ Temperature in curing Technology

curingSteps			Step One	Step Two	Step Three		Step Four		Step Five	Step Six	Step Seven	Step Eight
Intelligentialzed Biomass curingHouse	Set Temperatures	Dry Balls	35.4	38.1	40.2	42.0	44.9	48.0	50.6	54.5	59.3	68.0
		Wet Balls	33.9	35.7	36.0	36.0	36.8	36.5	38.0	38.8	40.3	42.0
Coal-burning curingHouse		Dry Balls	35.0	38.0	40.0	42.1	45.7	48.0	50.7	54.3	60.3	68.0
		Wet Balls	33.7	35.2	35.5	35.9	36.7	37.0	38.2	38.8	39.9	41.7

3 Results and Analysis
3.1 Technology of Intelligentialized Biomass curing
According to the results, there are eight curing steps in the intelligentialized biomass curing house: Step one is （the initial stage of tobacco-turning-yellow).The dry balls temperature in step one is 35-36℃, while that of the wet balls is 34℃ with the heating speed of 1℃/hour lasting 5-10 hours. 10 cm of the bottom layer of the tobacco leaves turns yellow during Step One. In Step Two (middle stage of tobacco-turning-yellow) the temperature of the dry balls and wet balls are 38 ℃ and 36℃ respectively with the heating speed of 0.5-1℃/hour lasting 18-30 hours. Most tobacco leaves turn 80-90 percent yellow. In Step Three (the final stage of tobacco-turning-yellow), the dry balls and wet balls temperature are 40-42 40-42℃ and 36-37℃ respectively with the heating speed of 0.5-1℃/hour lasting 20-30 hours. During this step the whole tobacco leave except for its main vain turns yellow. In Step Four(initial stage of color-drying   )the dry balls and wet balls temperature are 45-48℃ and 37-38℃ respectively with the heating speed of 0.3-0.5℃/hour lasting 10-24 hours when main veins of the leaves become both yellow and soft. In Step Five( middle stage of color ) the dry balls and wet balls temperature are 50℃ and 38-39℃ respectively with the heating speed of 0.5-1℃/hour lasting 8-10 hours when the veins and the whole leaves turn yellow.
                 Table.2 Technology Parameters in Traditional Coal-burning and Intelligentialized  Biomass curing

Types of curingHouse	curingSteps	Set Temperature（℃）		Real Temperature（℃）		Changes of Tobacco Leaves		Time（h）
		Dry Balls	Wet Balls	Dry Balls	Wet Balls	Percent of Yellowing Parts（%）	Percent of Drying Parts（%）
	Before Baking	-	-	27.3	25.8	-	-	-
Intelligentialized Biomass curingHouse	Step 1	35.4	33.9	32.6	31.1	4.9	0.6	7.2
	Step 2	38.1	35.7	37.8	35.2	34.3	6.1	27.6
	Step 3	40.2	36.0	40.0	36.0	50.7	17.1	12.6
		42.0	36.0	41.7	36.0	69.9	30.6	17.2
	Step 4	44.9	36.8	44.7	36.8	86.1	42.2	12.0
		48.0	36.5	47.4	36.8	98.1	60.5	12.0
	Step 5	50.6	38.0	49.9	38.1	100.0	73.3	10.0
	Step 6	54.5	38.8	53.4	38.8	100.0	76.2	12.6
	Step 7	59.3	40.3	59.0	40.9	100.0	86.7	18.0
	Step 8	68.0	42.0	66.1	41.8	100.0	96.5	19.3
Traditional Coal-burning curingHouse	Before Baking	-	-	27.7	25.9	-	-	-
	Step 1	35.0	33.7	33.8	32.0	4.9	1.0	14.3
	Step 2	38.0	35.2	37.7	35.1	37.4	8.8	25.7
	Step 3	40.0	35.5	39.7	35.2	51.9	13.8	12.0
		42.1	35.9	41.7	35.8	67.7	28.0	17.0
	Step 4	45.7	36.7	45.0	36.6	79.0	40.7	10.0
		48.0	37.0	47.9	37.0	97.5	59.0	10.7
	Step 5	50.7	38.2	50.5	38.3	100.0	62.5	10.0
	Step 6	54.3	38.8	53.1	38.7	100.0	75.4	10.3
	Step 7	60.3	39.9	60.5	39.9	100.0	85.0	18.0
	Step 8	68.0	41.7	67.4	41.1	100.0	95.9	18.7

 
3.2   Comparison of Benefits between Traditional Coal-burning Curing House and Intelligentialized Biomass Curing House
3.2.1 Comparison of Fuel Costs
It can be seen from Table 4. The costs of coal is 830 RMB/ton while that of the biomass briquette fuel is 780RMB/ton. In the traditional coal-burning curingthe average fuel consumption of the lower leaf, middle leaf and the upper leaf are 745 kg/brick bed,815 kg/brick bed,885 kg/brick bed respectively and their costs are 618.35 RMB/brick bed,676.45RMB/brick bed,734.55RMB/brick bed . While in the intelligentialized biomass curing the fuel consumption in the three parts in are 712 kg/brick bed,774kg/brick bed,827kg/brick bed and the costs are 555.36yuan/brick bed,603.73yuan/brick bed,645.06yuan/brick bed. Compared with coal-intensive curing house, using intelligentialzed biomass intensive curing house can considerably reduce fuel consumption in each part of tobacco leaves thus cut down their costs. Specifically the fuel costs of each part can be reduced by 9.00 yuan, 8.08 RMBand 8.14 RMBrespectively.
             
3.2.2 Labor-efficiency Comparison
According to the statistics provided by the local tobacco-curing institutions, taking into consideration the labor used in curing the lower parts, the middle parts and the upper parts of the tobacco leaves, the average labor used in adding coal and cleaning coal dash is 30 hours/brick bed. If one worker is able to take of 10 coal-burning curing houses and his wage is 2500/month, the effective working time wage(yuan/hour) is then 2500/(30*10)=8.3 yuan/hour.
4 Conclusion
The following points should be paid attention in the intelligentialized baking. Firstly, Check the equipment before baking. Specifically check whether the dust in the furnaces is cleaned. Secondly check whether the circuit of the main control probe works properly, whether the kettle leaks, whether the gauze is cleaned, whether the cold air inlet valve is sensitive. Thirdly, check whether the probe is installed in the right place since the two groups of censors should be hung on the top and at the end of the tents respectively with a distance of 2 meters.The censors should be installed on the hanging beam 1 meter from the right side wall, with its surface facing the floor and with the vertical height of 60-70cm. Fourthly, check whether the ventilation is well-distributed. Then check whether the power system works well.2. Pay attention to the observing the curing process. The first thing to be remembered is that if it’s rainy the drought fans should be started 1-2 hours in advance before the leaves are baked. Secondly if the fuel is not fully burned or the fuel adding is not smooth so that the fire goes out, the grate bridge has to be dragged to clean the dust every 3-4 hours a day.Last when adding fuel try not to put in fuel powders in case the furnace is blocked.If the fuel conveying is not smooth sledge hammer can be used to pat the equipment slight or higher the conveying speed until it becomes normal.
    Besides, for the curing of special tobacco leaves attention to the following points: 1. For the leaves with less water the color has to be fixed before they are hydrated. When they are too dry water has to be added in the house in the middle and final period of yellowing. For the leaves with high nitrogen application rate, the starting temperature should be high(40-42℃)since these leaves are more difficult to be hydrated and yellowed and are less resistant to baking.In the color drying period the heating should be adjusted fast to prevent the leaving from turning black. 4.For the leaves that are over-baked, over-yellowed and are too thin the starting temperature need to be set between 38-40℃. The wet balls’ temperature has to be relatively low at 35-37℃. The hydration process has to be sped up to decrease the consumption of dry substances. The yellowing process and the color-drying process have to be conducted simultaneously. As water in the tobacco leaves decreases the temperature has to be risen to prevent the dry substances from losing and the leaves from being over-yellowed to become black, especially the lower parts leaves which are  already mature when they were harvested.
 
References
[1]  Chaopeng Song, Changjun Li, Chao Yang.et al “The Application Prospect of Biomass Energy in Tobacco Curing”,Agricultural Science of Hebei Privince,2008,24(3),58-60.
[2] Li Wang, Xueming Li, Yan Xu, “Economic Loss Research of Straw Burning In Mainland China”, Resources and Environment of Drought Area,2008, 20(8),170-175.
[3] Zhenhong Yuan, Chuangzhi Wu, Longlong Ma, Biomass Energy Application Principle and Technology, (Chemistry Engineering Press), 2005, 17(6), 51-56.
[4] Wenjie Wang, Feng Li, Xiujiang Yue, “Study on the Application of Biomass Briquette and Burner in Tobacco Curing”, Modern Agricultural Science, 2013 , 15(2), 112-119.