Inventory Data Collection

Inventory data were collected to get an overview of the process for each factory. Data collected include materials (rubber and chemicals) consumption, energy consumption, water consumption, air emission and wastewater quality. The flow diagram of the overall process of natural rubber latex concentrate is shown in the Figure 3.4

Process of Separation Process of Coagulation Latex Concentrate Field Latex Skim latex

Block Skim Rubber

Figure ‎3.4: Overall Process Flow in Natural Rubber Latex Concentrate Processing

3.4.1. Material Inventory

Materials were divided into two parts, rubber balance and chemical consumption.

3.4.1.1. Rubber

Rubber balance is made to determine the concentration or amount of overall dry rubber which will show the amount of rubber in the input and output of the process. Figure 3.3 shows that the input of the process contained rubber with known composition from laboratory analysis. The outputs that contain rubber such as in the pond, skim latex and losses were also obtained from laboratory analysis. Losses or waste were obtained by doing rubber balance which then give the efficiency and impact to environment from natural rubber latex concentrate processing.

P R O C E S S Field latex Chemicals Energy Water Skim latex Water Losses Wastewater Air Emission Main Product: Latex Concentrate P R O C E S S Product:

Block Skim Rubber Lump

Energy Chemicals

Rubber balance will show the composition of rubber in field latex (input) and rubber output as main material in latex concentrate. The difference between rubber input and output in main product and by product is waste and will be used in eco-efficiency indicator determination. Data of rubber balance will be obtained directly from the records of the natural rubber factories.

3.4.1.2. Chemicals

Chemicals used in natural rubber latex concentrate processing have the ability to pollute the environment. These data are needed to evaluate the impact to the environment and will be obtained directly from the records of natural rubber latex concentrate processing.

3.4.2. Energy consumption

Energy in natural rubber latex concentrate processing can be divided into two parts, the energy used to produce concentrated latex and block skim rubber. The energy is required to move the rotator during mixing for the purpose of homogenizing the chemical preservatives and energy is also consumed in the centrifuge to separate rubber and non rubber. The equipments that consume energy in latex concentrate processing are onvangen tank, centrifuge, mixer and storage tank. Process production of block skim rubber also use energy to move the conveyor, for cutting tools, pressing, and in the drying process. The equipments that consume energy in block skim rubber are fan basin, macerator, creper, hammer mill, dryer and pressing. Energy consumption data is used to identify the impact to environment during process phase and obtained directly from the records in natural rubber latex concentrate processing. Energy consumption data will be used in energy intensity indicator as one of the indicators in eco-efficiency.

3.4.3. Water consumption

Most of the water is used to coagulate skim latex, others for cleaning the equipment and washing the rubber lumps from plantation and solid rubber from coagulation pond. Water consumption in natural rubber latex concentrate processing will be used to determine the impact to environment due to water consumption and to identify water intensity indicator in eco-efficiency indicator determination. Water consumption data will be obtained directly from the records of natural rubber latex concentrate processing.

3.4.4. Residual

The processing of natural rubber latex concentrate also produces some residues including gas, liquid and solid. Gas residue comes from chemical use, such as ammonia and fuel combustion. Liquid residuals known as wastewater mainly consist of water, which comes from cleaning of equipments in latex concentrate processing, washing the coagulum and rubber lumps and from latex itself in block skim rubber processing. Solid residue is rubber that did not participate as a product either in latex concentrate and block skim rubber. Solid are usually found in wastewater from coagulation pond have poor quality and sell at a lower price.

3.4.4.1.Gas

Gas as part of the residue in natural rubber latex concentrate processing will create air emissions. Air emissions are emissions generated during the process, which comes from stationary source, such as generator, dryer, and boiler. Air emissions data are obtained by direct measurement of parameters in accordance to the standard parameter set by the regulation of the Ministry of Environment Republic of Indonesia, Kep- 13/MENLH/3/1995 on standards of quality for air emission from stationary source as shown in Table 3.1. These data are needed to determine if these emissions are still

within the permissible limits. These data will also be associated with the impact on the environment as well as eco-efficiency in the natural rubber latex concentrate processing.

Table ‎3.1: Standards of Quality Air Emission from Stationary Source No Parameter Standard Requirement(mg/m3)

1 SO2 1500

2 NO2 800

3 Particulate 150

Source: Ministry of Environmental Republic of Indonesia,(1995b).

3.4.4.2. Liquid

Liquid as part of the residue is in the form of wastewater in natural rubber latex concentrate processing. Wastewater generated in natural rubber latex concentrate processing is managed to meet the established standards by Decree of Environment Ministry Republic of Indonesia, KEP-MEN LH-No 51, 1995, with regards to wastewater quality standard for industrial activities as shown in Table 3.2. Effluent data were obtained by taking samples on site at the last pond that are ready to be released to water body and the parameters are measured in the laboratory. These data re needed to determine the chemical content in wastewater and to determine if it is still within the permissible limits.

Source: Ministry of Environmental of Republic Indonesia, (KLH, 1995a)

3.4.4.3. Solid

Solid refers to rubber that did not contribute as a product either in latex concentrate and block skim rubber. In this research, solid waste is usually found in wastewater from coagulation pond and possess poor quality and thus sells at a lower price.