Prosecution Insights
Last updated: May 29, 2026
Application No. 17/673,998

CARBON-NEGATIVE METALLURGICAL PRODUCTS

Non-Final OA §103
Filed
Feb 17, 2022
Priority
Feb 18, 2021 — provisional 63/151,026
Examiner
HENDRICKSON, STUART L
Art Unit
1736
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Carbon Technology Holdings LLC
OA Round
3 (Non-Final)
72%
Grant Probability
Favorable
3-4
OA Rounds
0m
Est. Remaining
80%
With Interview

Examiner Intelligence

Grants 72% — above average
72%
Career Allowance Rate
708 granted / 979 resolved
+7.3% vs TC avg
Moderate +8% lift
Without
With
+8.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
30 currently pending
Career history
1017
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
79.8%
+39.8% vs TC avg
§102
0.7%
-39.3% vs TC avg
§112
8.2%
-31.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 979 resolved cases

Office Action

§103
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. The RCE is accepted. Prior art rejections Claims 1-26 and 30 are rejected under 35 U.S.C. 103 as being unpatentable over Cagigas 20200346929, alone or taken with Despen et al. 8920525, and further in view of Kuzyakov article. Cagigas teaches, especially in paras 21, 28 and 43-44, making char from biomass with optional additives. Since biomass is the source, the renewability is deemed met; see para 29. In any event, using fresh biomass is obvious to prevent loss of carbon and pollution from rotting. Paragraph 4 teaches a carbon negative process, and no patentable distinction is seen from a negative product. For the fixed carbon, paragraph 3 teaches optimization of properties for desired result; note table 2 and para 33. Using the appropriate calculation method is obvious to assure accuracy. In so far as the renewability (C14) is not explicitly discussed and may differ from the claimed value, Kuzyakov teaches optimizing C14 ratio; see pgs. 212-213. Doing so is obvious to achieve the benefits noted and optimize the feedstocks that can be used. For claims 2-5, no difference is seen since the product is/can be the same. For claims 6-7, table 2 teaches 79% carbon product. For claims 8-9, holding moisture is taught and the claimed levels are obvious to optimize the use as a fertilizer or animal feed, noting that moisture can help bind a composition. For claim 10, Table 1 recites impurities in the product. Note the use in feed or fertilizer. For claim 11, the amount added is obvious to make a more effective feed or fertilizer. For claims 12 and 13, the unreacted feed material can be combusted and can be grown again. For claim 14, the impurity metals are carbon neutral, being inorganic and naturally occurring, and thus includes minerals added to the feed. It is obvious to use neutral items to cut CO2 generation. For claim 15, using a binder is obvious to incorporate it into animal feed. For claims 16-18, note that unconverted feed can be present in the product. For claim 19, the process by which starch was made is not relevant to the product claimed. For claim 20, the physical contact of the additive will impede the ability to sorb materials since pores and surface area are no longer accessible. For claim 21, the carbon has ability to sorb materials, see para 31. Claim 22 is suggested by para 39 and 43; no differences are seen in the properties of the carbon. For claims 23-26, pellet form is suggested by use in animal feed, with the properties obvious (in not possessed) to be useful therein and maintaining their form yet be chewable. For claim 30, it is renewable because it is biomass. The examiner takes Official Notice that some of the additives claimed are old and known in fertilizer compositions, thus using them is obvious. In so far as the negative is a comparative to a different process or is dependent upon things not directly a part of the process (e.g. sources, transport), Despen teaches in col. 22-23 locating the factory near the biomass source. Doing so saves transport time and costs and makes the carbon negative versus a process requiring more transport or as defined by GREET. Claims 1-26 and 30 are rejected under 35 U.S.C. 103 as being unpatentable over Cheiky et al. 20130025190, alone or taken with Despen et al. 8920515, and further in view of Kuzyakov article. Cheiky teaches, especially in paras. 3-7 and 86-89 and figs. 10-12, a life-cycle-scheme of making carbon products and other materials in an efficient manner. The carbon product is said to be negative; para 30. No difference is seen, noting especially the comments above and the fact that it is made from biomass. Since biomass is the source, the renewability is deemed met. In any event, using freshly cut biomass is obvious to prevent loss of carbon and pollution from rotting. While the exact carbon content is not specified, it is obvious to efficiently make the desired product and no difference is seen due to it being from biomass. Para 110 discusses the process and concludes that it is the liquid product is negative, but if they had wanted to could have simply declared that the product was since both resulted from the process. Thus, this is merely an accounting choice based upon economic/social pressures or incentives (tax credits) from whatever entities concerned them most. Cheiky does not teach the C14 ratio, however in so far as the biomass used does not meet the claims, Kuzyakov teaches optimizing C14 ratio; see pgs. 212-213. Doing so is obvious to achieve the benefits noted and optimize the feedstocks that can be used. The carbon is ‘renewable’ because if it converts to CO2, then that CO2 can be reconverted to carbon. Therefore, it appears that no matter the isotope ratio, it will be 100% renewable. For claims 2-5, no difference is seen since the product is/can be the same. For claims 6-7, high carbon is obvious as noted above. For claims 8-9, the claimed levels are obvious to optimize the use as a fertilizer, noting that moisture can help bind a composition. For claim 10, Paras 66 and 74-76 teach mixing with compost or plant nutrients or microbes. For claim 11, the amount added is obvious to make a more effective fertilizer. For claims 12, the microbes can be combusted. For claim 13, the compost biomass can be grown again. For claim 14, using neutral nutrient materials is obvious to cut CO2 generation. For claim 15, using a binder is obvious to incorporate it into fertilizer, noting that moist compost can act as a binder. For claims 16-18, compost contains lignin and starch. For claim 19, the process by which starch was made is not relevant to the product claimed. For claim 20, the physical contact of the additive will impede the ability to sorb materials since pores and surface area are no longer accessible. Claims 21 and 22 are suggested by para 74; no differences are seen in the properties of the carbon. For claims 23-26, pellet form is obvious for use as a fertilizer. For claim 30, it is renewable because it is biomass. The examiner takes Official Notice that some of the additives claimed are old and known in fertilizer compositions, thus using them is obvious. In so far as the negative is a comparative to a different process or is dependent upon things not directly a part of the process (e.g. sources, transport), Despen teaches in col. 22-23 locating the factory near the biomass source. Doing so saves transport time and costs and makes the carbon negative versus a process requiring more transport or as defined by GREET. Applicant's arguments filed 2/9/26 have been fully considered but they are not persuasive. The extensive documentation provided and direct answers to the questions posed are sincerely appreciated. The ratio argument is addressed above by the use of fresh biomass. No differences are seen. Kuzyakov is cited as an additional reference in case the primary references do not inherently meet the claims. Given that it discusses charred biomass, it is relevant to the primary references. Perhaps addressing the following comments will shed more light on the issues above. The 9 page document assumes technological progress in solar energy generation by 2035. It is not clear why this assumption is made- it is easy to ‘solve’ problems through optimistic assumptions. In the 38 page document, why do some of the bars on pg. 33 start below zero? In the 24 page document, assumptions are made about future energy supply out to 2050 in Table A-1. The ones concerning solar vary widely. Most estimates seem realistic, considering the weather and physical nature of the various places and the length of time it takes to build nuclear plants. Some seem to ignore the rosy future of solar power in point 1 however. /STUART L HENDRICKSON/Primary Examiner, Art Unit 1736
Read full office action

Prosecution Timeline

Feb 17, 2022
Application Filed
Feb 20, 2025
Non-Final Rejection mailed — §103
Aug 18, 2025
Response Filed
Nov 10, 2025
Final Rejection mailed — §103
Feb 09, 2026
Request for Continued Examination
Feb 11, 2026
Response after Non-Final Action
Mar 05, 2026
Non-Final Rejection mailed — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12636632
CARBON-CARBON COMPOSITE SORBENT FORMULATIONS FOR CARBON DIOXIDE ADSORPTION, AND RELATED METHODS
2y 0m to grant Granted May 26, 2026
Patent 12614735
COMPOSITION OF AND METHOD FOR OPTIMIZING A CATALYTIC REACTION
3y 11m to grant Granted Apr 28, 2026
Patent 12611649
BIOGENIC ACTIVATED CARBON AND METHODS OF MAKING AND USING SAME
2y 4m to grant Granted Apr 28, 2026
Patent 12605692
LIQUID ABSORBING BODY
4y 2m to grant Granted Apr 21, 2026
Patent 12606442
METHODS AND SYSTEMS FOR PRODUCING SOLID INORGANIC CARBONATE AND BICARBONATE COMPOUNDS
3y 1m to grant Granted Apr 21, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

Strategy Recommendation AI-generated — please review before filing

Get a prosecution strategy drawn from examiner precedents, rejection analysis, and claim mapping.
Typically takes 5-10 seconds — AI-generated, attorney review required before filing

Prosecution Projections

3-4
Expected OA Rounds
72%
Grant Probability
80%
With Interview (+8.0%)
3y 1m (~0m remaining)
Median Time to Grant
High
PTA Risk
Based on 979 resolved cases by this examiner. Grant probability derived from career allowance rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month